Cannula for external drainage of subretinal fluid

ABSTRACT

A cannula device for draining sub-retinal fluid externally to the eye includes a shaft, an outer sleeve, and an inner sleeve. The outer sleeve and the inner sleeve have a curve therein to access the back of the eye externally. The outer sleeve is extendable relative to the inner sleeve and the shaft, and the outer sleeve includes a penetrative tip to penetrate the sclera and provide access to the sub-retinal fluid to the inner sleeve.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.15/328,385, filed Jan. 23, 2017, which is a U.S. Nationalization of PCTApplication Number PCT/US2015/042942, filed on Jul. 30, 2015, whichclaims priority to and the benefit of U.S. Provisional PatentApplication 62/031,065 filed Jul. 30, 2014, entitled “SUBRETINAL CANNULAFOR OPHTHALMIC USE,” the disclosures of which are incorporated herein byreference in their entireties.

BACKGROUND OF THE DISCLOSURE

A variety of ocular surgery requires the drainage or removal of retinalfluid. In particular, subretinal fluid (“SRF”) is drained duringsurgical repair of retinal detachment (“RD”) in scleral bucklingsurgery, pars plana vitrectomy, or pneumatic retinopexy. More recently,surgical procedures have been developed to inject fluids and stem cellsunder the retina to treat certain degenerative retinal conditions.

RD is a condition where intraocular fluid passes under the retina from ahole within the retina. The intraocular fluid enters a space between theretina and the choroid. Once between the retina and the choroid, the SRFlifts up the retina, causing the retina to come away from its normalattachment to the choroid at the back of the eye. RD can lead toirreversible blindness in the patient if the retina is not fixed in atimely manner. In certain other conditions when there is inflammation inthe eye, the retina may have SRF develop under the retina without ahole. The end result is the same where it results in irreversibleblindness.

RD may be conventionally addressed using scleral buckling, pars plana(“PP”) vitrectomy, or pneumatic retinopexy. Scleral buckling includesthe application of a silicone sponge, rubber, or semi-hard plastic tothe exterior of the sclera by the operating professional.Conventionally, the buckling element is left in place permanently. Thebuckling element compresses the sclera toward the center of the eye,relieving traction on the retina, allowing the RD to settle against thewall of the eye.

Pars plana vitrectomy includes the removal of vitreous fluid from thevitreous chamber of the eye behind the lens. The vitreous fluid isconventionally removed through the pars plana adjacent the iris andciliary body. To fix a RD via the pars plana vitrectomy routedisadvantageously involves the penetration of the retina to provide adrainage path of the SRF.

Pneumatic retinopexy includes the introduction of a gas bubble having adifferent density than the vitreous fluid in the eye. The buoyancy ofthe gas bubble in the vitreous fluid enables the gas bubble to apply aforce to the detached portion of the retina and urge the retina backinto the proper position. More importantly, the gas bubble closes theretinal hole thereby preventing further entry of vitreous fluid underthe retina. The retina is then secured via cryopexy, photocoagulation,or other fixation method.

In each procedure, the removal of the SRF allows the proper placement ofthe retina apposed against the inside of the back of the eye and allowsthe retina to be more reliably secured in place. Incomplete removal ofthe SRF results in the inability of the retina to function leading toblindness. Additionally, any further damage to the retina can introduceadditional holes or tears through which intraocular fluid may reenterthe space behind the retina, resulting in an increased risk of RD.Therefore, a device and method for the reliable and complete removal ofSRF from behind the retina is desirable.

BRIEF SUMMARY OF THE DISCLOSURE

This summary is provided to introduce a selection of concepts that arefurther described below in the detailed description. This summary is notintended to identify specific features of the claimed subject matter,nor is it intended to be used as an aid in limiting the scope of theclaimed subject matter.

In an embodiment, a cannula device includes a shaft, an outer sleevewithin the shaft, and an inner sleeve within the outer sleeve. The shafthas a longitudinal axis. The outer sleeve is longitudinally slidablerelative to the inner sleeve. The outer sleeve has a penetrative tipthat protrudes distally from the shaft. The penetrative tip defines adistal axis at angle to the longitudinal axis in a range of 30° to 90°.A guard connected to the shaft extends transversely to the shaft.

In another embodiment, a cannula device includes a handle, a shaftextending from the handle, an outer sleeve partially within the shaft,and an inner sleeve at least partially in the outer sleeve. The outersleeve is longitudinally slidable relative to the shaft and having apenetrative tip at a distal end. The position of the outer sleeverelative to the shaft is at least partially determined by the controlmember. The shaft has a deflection portion that defines a distal axis atan angle to the longitudinal axis in a range of 30° to 90°. The innersleeve is longitudinally stationary relative to the shaft. A guard isconnected to the shaft and extends radially away from the shaft. Theguard has a curved distal surface and a proximal surface.

In yet another embodiment, a cannula device includes a shaft, a flexibleouter sleeve partially within the shaft, and an inner sleeve at leastpartially in the outer sleeve. The outer sleeve is longitudinallyslidable relative to the shaft and having a penetrative tip at a distalend. The position of the outer sleeve relative to the shaft is at leastpartially determined by the control member. The shaft has a deflectionportion that defines a distal axis at an angle to the longitudinal axisin a range of 30° to 90°. The inner sleeve is longitudinally stationaryrelative to the shaft. A guard is connected to the shaft and extendsradially away from the shaft. The guard has a curved distal surface anda proximal surface. The outer sleeve is slidably movable between aretracted position and an inserted position. The inner sleeve protrudesdistally from the penetrative tip when the outer sleeve is in theretracted position.

Additional features of embodiments of the disclosure will be set forthin the description which follows. The features of such embodiments maybe realized by means of the instruments and combinations particularlypointed out in the appended claims. These and other features will becomemore fully apparent from the following description and appended claims,or may be learned by the practice of such exemplary embodiments as setforth hereinafter.

BRIEF DESCRIPTION OF THE DRAWINGS

In order to describe the manner in which the above-recited and otherfeatures of the disclosure can be obtained, a more particulardescription will be rendered by reference to specific embodimentsthereof which are illustrated in the appended drawings. For betterunderstanding, the like elements have been designated by like referencenumbers throughout the various accompanying figures. While some of thedrawings may be schematic or exaggerated representations of concepts, atleast some of the drawings may be drawn to scale. Understanding that thedrawings depict some example embodiments, the embodiments will bedescribed and explained with additional specificity and detail throughthe use of the accompanying drawings in which:

FIG. 1 is a side view of an embodiment of a cannula device, according tothe present disclosure;

FIG. 2 is a top view of the cannula device of FIG. 1, according to thepresent disclosure;

FIG. 3 is a front view of the cannula device of FIG. 1, according to thepresent disclosure;

FIG. 4 is a side cross-sectional view of another embodiment of a cannuladevice having an internal fluid chamber, according to the presentdisclosure;

FIG. 5 is a side cross-sectional view of an embodiment of a cannuladevice having a lateral fluid port therein, according to the presentdisclosure;

FIG. 6 is a side cross-sectional view of the cannula device of FIG. 5having the outer sleeve moved distally beyond the inner sleeve,according to the present disclosure;

FIG. 7 is a schematic representation of an embodiment of a cannuladevice penetrating the sclera of an eye, according to the presentdisclosure;

FIG. 8 illustrates the retraction of the outer sleeve of the cannuladevice in FIG. 7, according to the present disclosure;

FIG. 9 illustrates removal of sub-retinal fluid (“SRF”) from the eyethrough a lateral fluid port in an embodiment of a cannula device,according to the present disclosure; and

FIG. 10 illustrates removal of SRF from the eye into an internal fluidchamber of an embodiment of a cannula device, according to the presentdisclosure.

DETAILED DESCRIPTION

One or more specific embodiments of the present disclosure will bedescribed below. In an effort to provide a concise description of theseembodiments, some features of an actual embodiment may be described inthe specification. It should be appreciated that in the development ofany such actual embodiment, as in any engineering or design project,numerous embodiment-specific decisions will be made to achieve thedevelopers' specific goals, such as compliance with system-related andbusiness-related constraints, which may vary from one embodiment toanother. It should further be appreciated that such a development effortmight be complex and time consuming, but would nevertheless be a routineundertaking of design, fabrication, and manufacture for those ofordinary skill having the benefit of this disclosure.

One or more embodiments of the present disclosure may generally relateto constructing and using a cannula device for use in medicalprocedures. More specifically, the present disclosure may relate toconstructing and using a cannula device for the draining of sub-retinalfluid (“SRF”) from the eye. SRF is located behind the retina of apatient's eye and in the region of the eye where the retina hasdetached. The SRF may accumulate between the retina and the sclera, thefibrous outer layer of the eye. A cannula device may provide a fluidconduit through the sclera in the back of the eye to allow drainage ofthe SRF without penetrating the retina. Penetration of the retina maydelay and/or complicate recovery from the drainage of the SRF andreattachment of the detached retina. Penetration of the retina requiresentry into the eye from the pars plana route using a vitrectomytechnique.

A cannula device may include a handle with a shaft extending therefromin a distal direction. The shaft may house an inner sleeve and an outersleeve. The inner sleeve may provide a fluid conduit to drain the SRFfrom the eye. The outer sleeve may have a penetrative distal end thatmay penetrate the sclera and provide an opening therethrough. The innersleeve may be introduced to the eye through the opening, and SRF may bedrained therethrough. The outer sleeve may be retracted proximally afterpenetrating the sclera and prior to and/or while introducing the innersleeve such that the fluid conduit may be provided to drain the SRFwhile reducing the risk that the penetrative distal end of the outersleeve may damage the retina. The SRF may be drained into a fluidcompartment in the handle, or through a lateral port in the shaft.

FIG. 1 depicts a side view of an embodiment of a cannula device 100,according to the present disclosure. The cannula device 100 may includea handle 102 having a shaft 104 extending longitudinally therefrom in adistal direction. In some embodiments, the shaft 104 may besubstantially tubular, having an open space in the center thereof,allowing other components to be positioned and/or moved within the shaft104. In other embodiments, the shaft 104 may have non-circulartransverse cross-sections, such as rectangular, square, octagonal,elliptical, other regular shapes, irregular shapes, or combinationsthereof.

The shaft 104 may house an outer sleeve 106 therein. The outer sleeve106 may be longitudinally slidable relative to the shaft 104. In someembodiments, the outer sleeve 106 may be made of or include a flexibleand/or resilient material such that the outer sleeve 106 may have acurved and/or angled portion. The outer sleeve 106 may bend and/or flexupon longitudinal movement of the outer sleeve 106 relative to the shaft104 and may recover an original shape thereafter. In other embodiments,the outer sleeve 106 may include a shape memory material. For example,the outer sleeve 106 may be made of or include a nickel titanium alloy.In another example, the outer sleeve 106 may include a shape memorypolymer.

The outer sleeve 106 may house an inner sleeve 108 therein. The innersleeve 108 may be longitudinally fixed relative to the shaft 104. Theinner sleeve 108 may protrude distally from the outer sleeve 106 whenthe outer sleeve 106 is moved proximally and may be covered by the outersleeve 106 when the outer sleeve 106 is moved distally. The inner sleeve108 may provide a fluid conduit through which a fluid may be drainedduring a medical procedure, such as ocular surgery. While the cannuladevice 100 may be described in relation to ocular surgery and, inparticular, retinal detachment (“RD”), the cannula device 100 may beused in other procedures to remove fluids. The cannula device 100 alsomay be used to inject fluid under the retina from the exterior of theeye such as in delivering medication into the sub retinal space.

To provide fluid communication between an eye cavity and the fluidconduit of the inner sleeve 108, the outer sleeve 106 may include apenetrative tip 110 at the distal end of the outer sleeve 106. The outersleeve 106 may be moved distally to extend beyond the inner sleeve 108and penetrate the sclera of the eye and allow the inner sleeve 108 toenter the eye cavity. The penetrative tip 110 may include a bevelededge, a tapered edge, a serrated edge, or combinations thereof tofacilitate penetration of bodily materials.

To position the inner sleeve 108 and the penetrative tip 110 of theouter sleeve 106 relative to the eye cavity, the cannula device 100 mayinclude a guard 112 extending transversely from the shaft 104. In someembodiments, the guard 112 may be positioned to allow a chord length(i.e., length of the inner sleeve 108 extending distally of the guard112) in a range having upper and lower values including any of 2.0millimeters (mm), 2.25 mm, 2.5 mm, 2.75 mm, 3.0 mm, 3.25 mm, 3.5 mm,3.75 mm, 4.0 mm, 4.25 mm, 4.5 mm, or any value therebetween. Forexample, the chord length may be in a range of 2.0 mm to 4.5 mm. Inanother example, the chord length may be in a range of 2.5 mm to 4.25mm. In yet another example, the chord length may be in a range of 3.0 mmto 4.0 mm.

The position of the outer sleeve 106 relative to the shaft 104 and,hence, the position of the penetrative tip 110 relative to the innersleeve 108 may be controlled by a control member 114 protruding fromand/or positioned in the handle 102. The control member 114 may allowfor the direct or indirect longitudinal positioning of the outer sleeve106. In some embodiments, the control member 114 may be operablyconnected to the outer sleeve 106 by an adhesive, a mechanicalconnection (e.g., bolt, clamp, screw), a mechanical linkage, an integralconnection (e.g., brazing, welding), or combinations thereof. In otherembodiments, the control member 114 may be integrally formed with theouter sleeve 106. In some embodiments, moving the control member 114distally may move the outer sleeve 106 distally and moving the controlmember 114 proximally may move the outer sleeve 106 proximally. In otherembodiments, the movement and/or position of the outer sleeve 106 may bebiased by a biasing member. For example, the movement and/or position ofthe outer sleeve 106 may be biased by a spring, a magnet, a compressiblegas, a roller mechanism, or other biasing member that applies a proximalforce to the outer sleeve 106 to urge the outer sleeve 106 in theproximal direction. In such an example, a user may apply a distal forceto the control member 114 to overcome the proximal force of the biasingmember and move the outer sleeve 106 distally. For example, thepenetrative tip 110 may extend beyond the inner sleeve 108 while theuser applies a distal force to the control member 114 and, uponreleasing the distal force on the control member 114, the outer sleeve106 may move proximally at least partially due to the biasing member.

In some embodiments, the shaft 104 may have a length in a range havingupper and lower values including any of 2.0 centimeters (cm), 2.1 cm,2.2 cm, 2.3 cm, 2.4 cm, 2.5 cm, 2.6 cm, 2.7 cm, 2.8 cm, 2.9 cm, 3.0 cm,or any value therebetween. For example, the shaft 104 may have a lengthin a range of 2.0 cm to 3.0 cm. In another example, the shaft 104 mayhave a length in a range of 2.4 cm to 2.8 cm. In yet another example,the shaft 104 may have a length of about 2.6 cm. In some embodiments,the shaft 104 may include a longitudinal axis 116. The longitudinal axis116 may extend along the full length of the shaft 104 from the handle102 to the guard 112. In other embodiments, the shaft 104 may have oneor more curved portions. For example, the shaft 104 may include adeflection portion that deflects the outer sleeve 106 and the innersleeve 108 from the longitudinal axis 116 and may define a second,distal axis 118. In some embodiments, at least a portion of the outersleeve 106 and the inner sleeve 108 may be coaxial with the longitudinalaxis 116. In other embodiments, at least a portion of the outer sleeve106 and the inner sleeve 108 may be coaxial with the distal axis 118. Inyet other embodiments, at least a portion of the outer sleeve 106 and atleast a portion of the inner sleeve 108 may be coaxial with thelongitudinal axis 116 and at least a portion of the outer sleeve 106 andat least a portion of the inner sleeve 108 may be coaxial with thedistal axis 118.

The distal axis 118 and the longitudinal axis 116 may form a deflectionangle 120 of the distal portion of the cannula device 100. Thedeflection angle 120 may be in a range having upper and lower valuesincluding any of 30°, 40°, 50°, 60°, 70°, 80°, 90°, or any valuestherebetween. For example, the deflection angle 120 may be in range of30° to 90°. In another example, the deflection angle 120 may be in arange of 50° to 80°. In yet another example, the deflection angle 120may be in a range of 60° to 70°.

FIG. 2 is a top view of the cannula device 100 of FIG. 1. The shaft 104may extend from the handle 102 to the guard 112. The shaft 104 maycontain and/or direct the outer sleeve 106 operably connected to thecontrol member 114. While the control member 114 may control therelative position of the outer member to the handle 102 and shaft 104,the guard 112 may at least partially determine the position of thecannula device 100 relative to the patient's eye. The guard 112 maycontact the sclera and/or other portion of the eye to position thecannula device 100 in a known reference position. In some ocularsurgeries, the ability of the medical professional to visualize theprocedure may be limited. The guard 112 may provide a known referenceposition to reduce the risk of unintended and/or undesired movement ofthe cannula device 100. In some embodiments, the handle 102 may includeone or more markings on the handle to convey the relative position ofthe outer sleeve 106 and the control member 114. For example, the handle102 may have a plurality of graduations thereon to convey to a user thedistance to which the outer sleeve 106 has been moved in the distaldirection relative to a retracted position and/or the distance to whichthe outer sleeve 106 has been moved in the proximal direction relativeto the inserted position.

The guard 112 may have a distal face 122 and a proximal face 124. Insome embodiments, the distal face 122 may have a flat surface. In otherembodiments, at least a portion of the distal face 122 may be curved. Inyet other embodiments, at least a portion of the distal face 122 may beconcave in at least one direction. In at least one embodiment, thedistal face 122 may be concave with respect to two directions. A distalface 122 that is concave in two directions may replicate the curvatureof the eye and provide additional stability. In some embodiments, theguard 112 may have a solid distal 122 and/or solid proximal face 124. Inother embodiments, the guard 112 may have a wire frame distal face 122and/or wireframe proximal face 124. In some embodiments, the guard 112may be ovoid, square, rectangular, other regularly shaped, irregularlyshaped, or combinations thereof when viewed from a longitudinaldirection. The distal face 122 may have a transverse dimension(transverse to the longitudinal axis 116) in one or more directions in arange having upper and lower values including any of 2.0 mm, 3.0 mm, 4.0mm, 5.0 mm, 6.0 mm, 7.0 mm, 8.0 mm, or any value therebetween. Forexample, the guard 112 may have a transverse dimension in a range of 2.0mm to 8.0 mm. In another example, the guard 112 may have a transversedimension in a range of 3.0 mm to 7.0 mm. In yet another example, theguard 112 may have a transverse dimension in a range of 4.0 mm to 6.0mm. In another embodiment, the guard 112 may have a thickness betweenthe distal face 122 and the proximal face 124 in a range having upperand lower values including any of 1.0 mm, 2.0 mm, 3.0 mm, 4.0 mm, 5.0mm, or any value therebetween. For example, the guard 112 may have athickness in a range of 1.0 mm to 5.0 mm. In another example, the guard112 may have a thickness in a range of 2.0 mm to 4.0 mm. In yet anotherexample, the guard 112 may have a thickness of 3.0 mm.

FIG. 3 is a front view of the cannula device 100, showing the innersleeve and the penetrative tip 110 extending distally from the distalface 122 of the guard 112. When in a retracted position, as shown, thepenetration tip 110 may be in a proximal direction, exposing the innersleeve 108. In some embodiments, the inner sleeve 108 be colored orotherwise include a visual indicator thereon to assist in identifyingthe position of the inner sleeve 108 during a medical procedure. Inother embodiments, the penetrative tip 110 may be colored or otherwiseinclude a visual indicator thereon to assist in identifying the positionof the penetrative tip 110 during a medical procedure. In yet otherembodiments, the inner sleeve 108 and the penetrative tip 110 may havedifferent colors and/or visual indicators thereon to assist inidentifying the relative position of the inner sleeve 108 andpenetrative tip 110 during a medical procedure.

The penetrative tip 110 may include a sharpened edge 126 at thedistalmost end of the penetrative tip 110. In some embodiments, thesharpened edge 126 may include a beveled edge, a ground edge, a serratededge, a tapered edge, a single point, a plurality of points, orcombinations thereof to allow the penetrative tip 110 to more easilypuncture and/or penetrate bodily material, such as the sclera. In atleast one embodiment, the distalmost point of the penetrative tip 110may be located on a side of the penetrative tip 110 away from the guard112 (i.e., on the bottom or outside of the curved portion of thepenetrative tip 110) to reduce the risk of tearing of the sclera uponinsertion and/or removal of the penetrative tip 110.

In some embodiments, the penetrative tip 110 may have a diameter in arange having upper and lower values including any of 0.020 inches (in)(0.51 mm), 0.022 in (0.56 mm), 0.024 in (0.61 mm), 0.026 in (0.66 mm),0.028 in (0.71 mm), or any values therebetween. For example, thepenetrative tip 110 may have a diameter in a range of 0.020 in (0.51 mm)to 0.028 in (0.71 mm). In other examples, the penetrative tip 110 mayhave a diameter in a range of 0.022 in (0.56 mm) to 0.026 in (0.66 mm).In yet other examples, the penetrative tip 110 may have a gauge in arange of 22 gauge to 25 gauge (Needle wire gauge). In yet furtherexample, the penetrative tip 110 may have a gauge in a range of 23 gaugeto 24 gauge.

FIG. 4 is a side cross-sectional view of another embodiment of a cannuladevice 200 with an outer sleeve 206 and associated control member 214 ina retracted (i.e., proximal) position. The cannula device 200 mayinclude a shaft 204 connecting a handle 202 to a guard 212. The shaft204 may contain the outer sleeve 206, which may, in turn, contain aninner sleeve 208. The inner sleeve 208 may provide a fluid conduit 228through at least a portion of the inner sleeve 208. In some embodiments,the fluid conduit 228 may extend from a distal end of the cannula device200 through a deflection portion 230 and along the length of the shaft204 to the handle 202. In the handle, an internal fluid chamber 231 maybe in fluid communication with the inner sleeve 208. The internal fluidchamber 231 may receive fluid through the inner sleeve 208 from the bodycavity, such as the SRF from the eye cavity and allow the user to removethe fluid from the patient.

FIG. 5 is a side cross-sectional view of another embodiment of a cannuladevice 300 with a penetrative tip 310 and control member 314 in aretracted (i.e., proximal) position relative to the handle 302. In someembodiments, a cannula device 300 may route fluid through a lateralfluid port 332. The depicted embodiment of a cannula device 300 may havea fluid conduit 328 that does not extend through the entire length of aninner sleeve 308. In some embodiments, the fluid conduit 328 mayterminate at a block 334 positioned in the inner sleeve 308. The block334 may seal the fluid conduit 328, limiting or preventing the flow of afluid proximal of the block 334. The fluid conduit 328 may extendproximally through the inner sleeve 308 to the fluid port 332. Anexternal fluid chamber may be connected to the fluid port 332.

In some embodiments, the fluid port 332 may extend laterally through theinner sleeve 308, the outer sleeve 306 and the shaft 304. The innersleeve 308 and the shaft 304 may be stationary relative to one another,and the outer sleeve 306 may be longitudinally slidable relative to theinner sleeve 308 and the shaft 304. When the outer sleeve 306 is in aretracted position, the fluid port 332 may provide fluid communicationtherethrough. When the outer sleeve 306 is in an inserted (i.e., distal)position, as shown in FIG. 6, an outer sleeve port 336 may be misalignedlongitudinally with an inner sleeve port 338 and a shaft port 340. Thefluid conduit 328 may have no exit to a fluid chamber while the outersleeve 306 and control member 314 are in an inserted position.

When in an inserted position, the outer sleeve 306 may extend distallybeyond the inner sleeve 308. For example, the sharpened edge 326 may bethe distalmost point of the cannula device 300. The cannula device 300may, therefore, be configured to penetrate the sclera of the eye whilethe fluid conduit 328 is sealed by the longitudinally misaligned outersleeve port 336, inner sleeve port 338, and shaft port 340.

Referring now to FIG. 7, an embodiment of a cannula device 400 in aninserted position is shown penetrating an eye 442. The eye 442 includesan eye cavity 444 filled with a vitreous fluid. RD is the detachment ofthe retina 448 from the sclera 446. In some cases, an opening throughthe retina 448 may allow the vitreous fluid to pass behind the retina448 and allow the retina 448 to detach away from the sclera 446.

Upon detachment of the retina 448 from the sclera 446, SRF 450 may beginto accumulate in the space between the detachment of the sclera 446 andretina 448. The SRF 450 may apply a fluid pressure that may limit orprevent the ability to reattach the retina 448 to the sclera 446.Removal of the SRF 450 may allow the reattachment of the sclera 446 andretina 448. Fluid communication through the cannula device 400 may alsoallow the introduction of therapeutic agents to the eye 442 viainjections from the cannula device 400.

The control member 414 is shown in a distal position, which may beoperably connected to the outer sleeve, and urging the sharpened edge426 distally. In some embodiments, the sharpened edge 426 may penetratethe sclera 446, allowing at least a portion of the distal face 422 ofthe guard 412 to be in contact with at least a portion of the sclera446. In other embodiments, the sharpened edge 426 may penetrate thesclera 446 and enter the space between the sclera 446 and the retina448.

FIG. 8 depicts the retraction of the penetrative tip 410 of the cannuladevice 400 upon proximal movement of the control member 414 to aretracted position. The penetrative tip 410 may move proximally anduncover the inner sleeve 408. The inner sleeve 408 may provide a fluidconduit to remove at least a portion of the SRF 450 from the spacebetween the sclera 446 and the retina 448. The proximal movement of thepenetrative tip 410 may allow and/or facilitate further insertion of theinner sleeve 408 (e.g., movement of the cannula device 400 toward theeye 442) because the inner sleeve 408 is blunt at the tip and thereforeis less likely to damage the retina 448. As described herein, RD mayoccur when a retina 448 has an opening therethrough that allowsaccumulation of SRF behind the retina 448 from the eye cavity.Puncturing the retina 448 during removal of the SRF 450 may, therefore,result in further complications. After penetration of the sclera 446,the inner sleeve 408, and cannula device 400 as a whole, may be advanceddistally while the penetration tip 410 is moved proximally. In someembodiments, the cannula device 400 may be advanced toward the eye 442until the guard 412 contacts the eye 442.

FIG. 9 depicts an embodiment of a cannula device 500 having a lateralfluid port 532, similar to that described in relation to FIG. 5 and FIG.6. Referring to FIG. 9, the lateral fluid port 532 may be in fluidcommunication with a drainage tube 552 that communicates with anexternal fluid chamber 554. The cannula device 500 may, thereby providefluid communication between the eye 542 and the external fluid chamber554 to drain SRF 550 from the eye 542 to the external fluid chamber 554.In some embodiments, the external fluid chamber 554 may apply a negativepressure (relative to the eye 542) to the SRF 550 to draw the SRF 550from the eye 542 to the external fluid chamber 554. In otherembodiments, the ocular pressure of the eye 542 may urge the SRF 550from the eye 542. Conversely, as described herein, fluid from theexternal fluid chamber 554 can be injected through the cannula device500 into the space under the retina (sub retinal space) in order todeliver medications or other therapeutic agents.

FIG. 10 illustrates an embodiment of removal of SRF 650 from an eye 642into an internal fluid chamber 631 of a cannula device 600 and/orinjection of a therapeutic agent from the internal fluid chamber 631 tothe eye 642. The cannula device 600 may have a fluid conduit 628, asdescribed in relation to FIG. 4, that extends from a distal end of thecannula device 600 through at least part of the shaft 604 and handle 602to the internal fluid chamber 631. The internal fluid chamber 631 isshown in partially cutaway of the handle 602. The internal fluid chamber631 may have a volume in a range having upper and lower values includingany of 0.1 cubic centiliters (cc), 0.3 cc, 0.5 cc, 1.0 cc, 1.5 cc, 2.0cc, 2.5 cc, 3.0 cc, or any values therebetween. For example, theinternal fluid chamber 631 may have a volume in a range of 0.1 cc to 3.0cc. In another example, the internal fluid chamber 631 may have a volumein a range of 0.5 cc to 2.0 cc. In yet another example, the internalfluid chamber 631 may have a volume of 1.0 cc.

In some embodiments, the internal fluid chamber 631 may include markingsor graduations 656 to assist a user in identifying how much SRF 650 hasbeen removed from the eye 642. For example, the graduations 656 may beinscribed, printed, written, embossed, or combinations thereof on theinternal fluid chamber 631. In other examples, the graduations 656 maybe inscribed, printed, written, embossed, or combinations thereof on thehandle 602. In some embodiments, the internal fluid chamber 631 may beremovable from the cannula device 600. For example, the internal fluidchamber 631 may be releasably connected to the handle 602 and/or theinner sleeve 608. The internal fluid chamber 631 and the inner sleeve608 may be connected through a threaded connection, a press fit, afriction fit, a snap fit, a mechanical interlock, other selectiveconnection mechanism, or combinations thereof.

In some embodiments, the internal fluid chamber 631 may include aplunger 658 or other device for applying a negative pressure to theinternal fluid chamber 631 relative to the fluid conduit 628 and theocular pressure of the eye 642. In other embodiments, a plunger 658 mayallow for more precise control of the volume of SRF 650 removed from theeye 642. For example, the plunger 658 may allow a user to stop and/orcontrol the rate of the drainage of SRF 650 from the eye 642.

The articles “a,” “an,” and “the” are intended to mean that there areone or more of the elements in the preceding descriptions. The terms“comprising,” “including,” and “having” are intended to be inclusive andmean that there may be additional elements other than the listedelements. Additionally, it should be understood that references to “oneembodiment” or “an embodiment” of the present disclosure are notintended to be interpreted as excluding the existence of additionalembodiments that also incorporate the recited features. Numbers,percentages, ratios, or other values stated herein are intended toinclude that value, and also other values that are “about” or“approximately” the stated value, as would be appreciated by one ofordinary skill in the art encompassed by embodiments of the presentdisclosure. A stated value should therefore be interpreted broadlyenough to encompass values that are at least close enough to the statedvalue to perform a desired function or achieve a desired result. Thestated values include at least the variation to be expected in asuitable manufacturing or production process, and may include valuesthat are within 5%, within 1%, within 0.1%, or within 0.01% of a statedvalue.

A person having ordinary skill in the art should realize in view of thepresent disclosure that equivalent constructions do not depart from thespirit and scope of the present disclosure, and that various changes,substitutions, and alterations may be made to embodiments disclosedherein without departing from the spirit and scope of the presentdisclosure. Equivalent constructions, including functional“means-plus-function” clauses are intended to cover the structuresdescribed herein as performing the recited function, including bothstructural equivalents that operate in the same manner, and equivalentstructures that provide the same function. It is the express intentionof the applicant not to invoke means-plus-function or other functionalclaiming for any claim except for those in which the words ‘means for’appear together with an associated function. Each addition, deletion,and modification to the embodiments that falls within the meaning andscope of the claims is to be embraced by the claims.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, the terms“approximately,” “about,” and “substantially” may refer to an amountthat is within less than 5% of, within less than 1% of, within less than0.1% of, and within less than 0.01% of a stated amount. Further, itshould be understood that any directions or reference frames in thepreceding description are merely relative directions or movements. Forexample, any references to “up” and “down” or “above” or “below” aremerely descriptive of the relative position or movement of the relatedelements.

The present disclosure may be embodied in other specific forms withoutdeparting from its spirit or characteristics. The described embodimentsare to be considered as illustrative and not restrictive. The scope ofthe disclosure is, therefore, indicated by the appended claims ratherthan by the foregoing description. Changes that come within the meaningand range of equivalency of the claims are to be embraced within theirscope.

1. A cannula device, the device comprising: a shaft having alongitudinal axis and having a fluid conduit extending through alongitudinal length thereof; a first sleeve partially within the shaftand longitudinally slidable relative to the shaft, the first sleevehaving a penetrative tip at a distal end protruding from the shaft, thepenetrative tip of the first sleeve defining a distal axis at an angleto the longitudinal axis in a range of 30° to 90°; a guard connected tothe shaft and extending transversely to the longitudinal axis, the innersleeve extending distally a chord length from the guard no more than 4.5millimeters; and a fluid chamber configured to store a therapeutic agentto be delivered through the penetrative tip of the first sleeve.
 2. Thecannula device of claim
 1. 3. The cannula device of claim 1, the guardhaving a deflection portion that deflects the first sleeve such that thedistal end of the outer sleeve is non-coaxial with the longitudinalaxis.
 4. The cannula device of claim 1, further comprising an innersleeve, the inner sleeve having a deflection portion that deflects thefirst sleeve such that a distal portion of the first sleeve isnon-coaxial with the longitudinal axis.
 5. The cannula device of claim1, the distal end of the first sleeve being oriented between 30° and 90°from the longitudinal axis.
 6. The cannula device of claim 1, the guardhaving a concave distal surface.
 7. The cannula device of claim 1, acontrol member being operably connected to the first sleeve andconfigured to move at least a portion of the first sleeve in alongitudinal direction.
 8. A cannula device, the device comprising: ahandle with a movable control member; a shaft extending from the handlehaving a proximal end, a distal end, and a longitudinal axis extendingtherebetween, the shaft having a deflection portion at the distal endthat is not parallel to the longitudinal axis, the deflection portiondefining a distal axis at an angle to the longitudinal axis in a rangeof 30° to 90°; a first sleeve partially within the shaft andlongitudinally slidable relative to the shaft, the first sleeve having apenetrative tip at a distal end and a position of the first sleeverelative to the shaft at least partially determined by the controlmember; a guard connected to the shaft, the guard extending radiallyaway from the shaft and having a curved distal surface and a proximalsurface; and a fluid chamber configured to store a therapeutic agent tobe delivered through the penetrative tip of the first sleeve.
 9. Thecannula device of claim 8, the first sleeve being made of a shape memorymaterial.
 10. The cannula device of claim 8, at least a portion of thefirst sleeve having a gauge in a range of 22 gauge to 25 gauge.
 11. Thecannula device of claim 8, further comprising a lateral fluid portextending transversely to the longitudinally axis through the shaft andthe first sleeve.
 12. The cannula device of claim 11, the first sleevehaving a retracted position and an inserted position, wherein an outerfluid port is longitudinally aligned with an inner fluid port in theretracted position and the outer fluid port is longitudinally misalignedwith the inner fluid port in the inserted position.
 13. The cannuladevice of claim 8, further comprising an internal fluid chamber in fluidcommunication with the inner sleeve.
 14. The cannula device of claim 13,the internal fluid chamber being releasably connected to the innersleeve. 15.-20. (canceled)
 21. A method of delivering a therapeuticagent into an eye of a patient, said eye having an outer portion, themethod comprising: inserting a sleeve of a cannula device into said eye,the cannula device having a guard extending transversely to alongitudinal axis of the sleeve, the sleeve extending distally a chordlength from the guard no more than 4.5 millimeters; continuing to insertthe sleeve of the cannula device into said eye until the guard contactssaid outer portion of said eye; delivering a therapeutic agent into saideye.
 22. The method of claim 21 where said eye includes a sub retinalspace, wherein continuing to insert the sleeve into said eye includescontinuing to insert the sleeve into said sub retinal space of said eyeuntil the guard contacts said outer portion of said eye.
 23. The methodof claim 21, wherein delivering the therapeutic agent includesdelivering a desired amount of therapeutic agent.
 24. The method ofclaim 23, wherein the desired amount of therapeutic agent is determinedusing markings or graduations on a fluid chamber associated with thecannula device.
 25. The method of claim 24, wherein the fluid chamberprovides a pressure relative to the fluid conduit to transmit thetherapeutic agent.